So here is my version- made from a silk charmeuse with a polka dot print. It was in one of my Fabric Mart bundles. I cut a 42 at the shoulders, and a 44 everywhere else, and I"m really happy with the fit. I didn't even add any length to it, which means that it is unusually long. If you're of average height, it may be a little long.
There's a center seam and darts in the back to give it some subtle shaping.